Method of and apparatus for increasing measurement sensitivity of fluorescence and luminescence

Abstract

A technique and apparatus for increased sensitivity fluorescence and luminescence emission measurements in which the emission volume is enclosed in a closely fitting cavity having highly reflecting diffuse material inner walls, and with a detector viewing as much of the radiant cavity walls as possible.

What is claimed is: 
     
       1. A method of increasing the sensitivity of measurement of fluorescing and/or luminescing light emitted from a volume, that comprises, enclosing the emission volume in a relatively closely fitting cavity enclosure; providing all of the inner walls of the cavity enclosing the volume with a highly reflecting diffuse material to enable all the light emitted from the emission volume inside the cavity to contribute to the radiance of the cavity inner walls, and the multiple reflections therefrom to increase the wall radiance; and positioning a detector to maximize its view of the radiant walls. 
     
     
       2. A method as claimed in claim 1 and in which the detector means is positioned for exposure through an aperture located substantially centrally of a wall of the cavity to enable said maximum view of the radiant walls. 
     
     
       3. For measuring the fluorescence and/or luminescence emitted from a volume, a cavity of dimensions slightly larger than the volume adapted to enclose such fluorescing and/or luminescing volume and enabling multiple reflections from the inner walls of the cavity, all of the inner cavity walls enclosing the volume being of highly reflecting diffuse material to enable the the fluorescing or luminescing light emitted inside the cavity to contribute to the radiance of the inner walls, and the multiple reflections therefrom to increase the wall radiance; and detector means positioned to maximize its view within the cavity of the radiant walls. 
     
     
       4. Apparatus as claimed in claim 3 and in which the detector means is exposed through an aperture located substantially centrally of a wall of the cavity to enable said maximum view of the radiant walls.